Apparatus for the reception and transmission of sound



July 20 1926. 1,593,457

Fig 1.

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- s. LAKHOVSKY APPARATUS FOR THE RECEPTION AND TRANSIISSION OF SOUND File by 14. 1924 3 Shasta-Sheet 2 6201:765Zakk ask: I?

Juy 20 1926.

G. LAKHOVSKY APPARA'iU FOR THE RECEPTION AND TRANSIISSIDII OP SOUND III 45 /IlIIIII/7/ II \\\\\\\\\\t Patented July 20, 1926.

UNITED STATES GEORGES LAKHOVSKY, OF PAR-IS, FRANCE.

APPARATUS FOR THE RECEPTION AND TRANSMISSION OF SOUND.

. Application filed May 14, 1924, Serial No The known apparatus for the reception or transmission of sound are generally formed by a metal boX or case wherein there is a vibratory diaphragm or plate which is in contact with this box and which also encloses the electric parts, such as magnets or electro-magnets in the case of receiving apparatus, or pieces of carbon (e. carbon granules) and their supporting means, envelopes, etc.", in the case of transmitting apparatus.

From this it results that on the one hand by reason of the contact of the plate with the box or case, the vibrations of the plate] are partially transmitted to the box or case, the resonance of which causes parasitic noises, which impair the purity of the sound. On the other hand this injurious effect is further increased by the setting in vibration of the box or case under the effect of the operation of the interior electric parts.

This invention has for its object to obviate this disadvantage by preventing the formation of these parasitic. noises, in such a manner that the sounds emitted or transmitted shall not be impaired and shall be perfectly pure.

This invention is characterized essentially in that the vibratory diaphragm or plate on the one hand and the internal electric parts on the other hand (magnets or electromagnets in the case of receiving apparatus, or pieces of carbon and their support or envelope in the case of transmitting apparatus) are isolated from the box or case enclosing these parts and from the cover thereof, in such a manner that the plate shall be shielded from any parasitic vibrations of the box or case, of the electric parts which it encloses, of the cover, and of the horn'or amplifier mounted on. the latter. Under these conditions the sounds produced are absolutely pure. p

This invention moreover has for its ob ject means for carrying it into practice. Such means forcarrying the invention into practice is characterized more especially by the following points 1. The vibratory plate or plates is or are mounted through the medium of a ring of india rubber or other suitable material on a box or case having a double wall, the annular space of which is filled with a material capable of damping vibration, such as paraffin, oil or the like.

2. The internal electric parts (magnets or 713,295, and in France November 29, 1923.

electromagnets in the case of receiving apparatus, or pieces of carbon and their envelope or support in the case of transmitting apparatus) are arranged in a box adjustahly mounted in the interior of the double walled box or case, which by its special construction is without resonance and thus completely isolates these parts from the plate or plates.

3. Preferably this box or case is covered with a plate serving to prevent any reciprocal action of the mass of air surrounding the interior electric parts and the mass of air in direct contact with the vibratory plate.

This invention is shown by way of eXa1nple only in the accompanying drawing, in which it is assumed to be applied to a telephonic receiver.

Figure 1 is a vertical section. V

Figure 2 is another section takenon a plane perpendicular to that of the preceding view.

Figures 3 and 4: illustrate two, modifications.

As shown in this drawing, the vibratory diaphragm or diaphragms a are framed in an india rubber ring 6 which is itself held fast between a shoulder c on the body of the apparatus and the rim Z of the cover.

The electromagnets c are mounted in a cylindrical box 7". This box is capable of sliding in the cylindrical recess formed by the interior wall 176 of a double-walled box or case i. The space is filled with paraffin or other suitable material. The latter is introduced through apertures L which can be afterwards closed by small screw plugs.

The position of the box f is determined by a screw Z which is fixed thereto and which extends through a nut m. The latter bears on its periphery a helical thread with which gears a worm a controlled from the exterior by means of a milled head 0. It will be read ily understood. that by operating this milled head the nut m is turned and the screw 7- and with it the box 7, is caused to rise or fall, which enables the position of the box and consequently that of the electromagnets to be adjusted relatively to the vibratory plate.

It is obvious that the adjusting means described can be replaced by rack and pinion or any other suitable mechanism.

The box 7 is preferably covered by a plate 5 serving to prevent any reciprocal action of ontaet with the vibratory plate.

The cover 1 18 also double-walled and tilled with paraffin or other suitable material. It is traversed by a tube Q tor permi ting the exit of the waves, and on which a horn can be fitted.

In the n'ioditication illustrated in Fig. 3, the ring 5 is retained by a metallic washer screwed within the flange of the cover. The screw thread-id portion of the cover serves also to screw the latter on the body it resuits therefrom that by screwing or unscrewing the cover, it possible to adjust the distance separating the electromagnets c from the plate a and t l at the mechanism Z m n 0 ot' the previous arrangement shown in Figs. 1 and 2 can be done away with.

The washer f can be replaced by a plate r, Fig. at, having a central opening :tor the passage of the electroiuagg'uet; this arrai'igcment has the advantage of reducing the volume of air which is under the plate. The diaphragm or plate a is set in a metallic mounting 25' isolated by two india rubber ashers u and o.

By reason of the above conditions the vibratory diaphragm or plate is shielded from any parasitic vibrations which may come either from the case or from the horn, or from the elements or parts such as electromagnets, etc, causing the n'iovement of such diaphragm or plate. In t ct the Vibratory movements of the diaphragm or plate cannot be communicated to the case by reason of the isolation ensured by the india rubber ring I) and or the presence of the damping material within the double wall Conversely, vibra tions or noises which may be produced by the operation of the exterior parts are also suppressed. The double walled cover clamps the vibrations of the horn.

Under these conditions, the diaphragm or plate a alone vibrates and the sounds cannot lose their natural quality by any parasitic noise and are absolutely pure.

The apparatus can be completed by horn havine a double wall tilled with a damping material. This arrangement of the horn completes the effect of he double-walled cover and ot the bores filled with damping material.

The new arrangements are especially applicable to loud speakers used in wireless telephony.

The above arran ements are obviously only given by way ot example, the forms, dimensions, materials employed and all detail arrangements can be varied in al cases without departing from the nature of the invcntion, as defined in the appended claims.

Claims 1. in an apparatus for the reception and transmission of sound, a vibratory membrane, parts tor causing this membrane to a double side in this box. conmaterial damping the vibrations, a iollow cover also containin a,- a material (.llllDplHQ; the vibrations.

In an amaaratus for the reception and transmission of sounds, a vibratory membrane, parts for *ausing this memln'ane to vibrate, a box enclosing the membrane and. said parts, a double side to this box contain ing a material damping the vibrations, a hollow cover also containing a material damping; the vibrations, a tube through the cover tor the passage of low sound waves.

l u an apparatus for the reception and transmission of sound, a vibratory mcmbrane enclosed in a rubber ring, parts caus (y t l parts, t; ining a his membrane to vibrate, a box enclosthe membrane and the said parts, a douside to this box containing a material cauiping the vibrations, and hollow cover is i containing a material damping the vibrations.

:l. In an apparatus for the reception and transmission of sound, a vibratory membrane enclosed in a rubber ring, parts to cause this membrane to vibrate, av box onclosinc the membrane and the said parts, a double side to this box containing a mate rial damping the vibrations, a hollow cover also containing a material. damping, the vibrations, enclosing the rubber ring between the cover and the box.

In an apparatus for the reception and transmission of sound, a vibratory plate, parts for causing this plate to vibrate, a double-walled box containing a substance that clamps vibrations, a double-walled cover "for the said box, filled with a material that damps vibrations.

The foregoing specification of my Improvements in appara us for the reception and. transmission of sound. signed by me this 30 day of April, 1924:.

oneness LAKHOVSI' r.

ll D. 

